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The Rosetta system-level specification language is a design language for complex, heterogeneous systems. Specific language design objectives include:

A system is a group of interacting or interrelated entities that form a unified whole. A system is delineated by its spatial and temporal boundaries, surrounded and influenced by its environment, described by its structure and purpose and expressed in its functioning. Systems are the subjects of study of systems theory.

A specification language is a formal language in computer science used during systems analysis, requirements analysis, and systems design to describe a system at a much higher level than a programming language, which is used to produce the executable code for a system.

Heterogeneous computing refers to systems that use more than one kind of processor or cores. These systems gain performance or energy efficiency not just by adding the same type of processors, but by adding dissimilar coprocessors, usually incorporating specialized processing capabilities to handle particular tasks.


In computer science, constraint programming is a programming paradigm wherein relations between variables are stated in the form of constraints. Constraints differ from the common primitives of imperative programming languages in that they do not specify a step or sequence of steps to execute, but rather the properties of a solution to be found. This makes constraint programming a form of declarative programming. The constraints used in constraint programming are of various kinds: those used in constraint satisfaction problems, linear inequalities, and others. Constraints are usually embedded within a programming language or provided via separate software libraries.

Composability is a system design principle that deals with the inter-relationships of components. A highly composable system provides components that can be selected and assembled in various combinations to satisfy specific user requirements. In information systems, the essential features that make a component composable are that it be:

In programming language theory, semantics is the field concerned with the rigorous mathematical study of the meaning of programming languages. It does so by evaluating the meaning of syntactically valid strings defined by a specific programming language, showing the computation involved. In such a case that the evaluation would be of syntactically invalid strings, the result would be non-computation. Semantics describes the processes a computer follows when executing a program in that specific language. This can be shown by describing the relationship between the input and output of a program, or an explanation of how the program will be executed on a certain platform, hence creating a model of computation.

Rosetta was undergoing standardization at various times.

Standardization or standardisation is the process of implementing and developing technical standards based on the consensus of different parties that include firms, users, interest groups, standards organizations and governments. Standardization can help maximize compatibility, interoperability, safety, repeatability, or quality. It can also facilitate commoditization of formerly custom processes. In social sciences, including economics, the idea of standardization is close to the solution for a coordination problem, a situation in which all parties can realize mutual gains, but only by making mutually consistent decisions. This view includes the case of "spontaneous standardization processes", to produce de facto standards.


The Rosetta effort emerged from a meeting in of the Semiconductor Industry Council's System-Level Design Language committee in 1996. The objective of the meeting was to define requirements for a next-generation design language that would address perceived shortcomings in existing languages such as VHDL and Verilog. Specific concerns included inability to represent constraints, lack of a formal semantics, inability to represent heterogeneous systems, and heavy reliance on computer simulation for analysis. In response to these requirements, three major approaches were pursued:

VHDL hardware description language

VHDL (VHSIC-HDL) is a hardware description language used in electronic design automation to describe digital and mixed-signal systems such as field-programmable gate arrays and integrated circuits. VHDL can also be used as a general purpose parallel programming language.

Verilog, standardized as IEEE 1364, is a hardware description language (HDL) used to model electronic systems. It is most commonly used in the design and verification of digital circuits at the register-transfer level of abstraction. It is also used in the verification of analog circuits and mixed-signal circuits, as well as in the design of genetic circuits. In 2009, the Verilog standard was merged into the SystemVerilog standard, creating IEEE Standard 1800-2009. Since then, Verilog is officially part of the SystemVerilog language. The current version is IEEE standard 1800-2017.

Computer simulation simulation, run on a single computer, or a network of computers, to reproduce behavior of a system; modeling a real physical system in a computer

Computer simulation is the reproduction of the behavior of a system using a computer to simulate the outcomes of a mathematical model associated with said system. Since they allow to check the reliability of chosen mathematical models, computer simulations have become a useful tool for the mathematical modeling of many natural systems in physics, astrophysics, climatology, chemistry, biology and manufacturing, as well as human systems in economics, psychology, social science, health care and engineering. Simulation of a system is represented as the running of the system's model. It can be used to explore and gain new insights into new technology and to estimate the performance of systems too complex for analytical solutions.

  1. Extending hardware description languages including VHDL and Verilog
  2. Extending programming languages including C and C++
  3. Defining new languages

The first approach ultimately resulted in SystemVerilog and extensions to VHDL while the second resulted in SystemC, all of which became Institute of Electrical and Electronics Engineers (IEEE) standards for the semiconductor industry. Rosetta's original application domain was system on a chip semiconductor systems. [1]

SystemVerilog hardware description and hardware verification language

SystemVerilog, standardized as IEEE 1800, is a hardware description and hardware verification language used to model, design, simulate, test and implement electronic systems. SystemVerilog is based on Verilog and some extensions, and since 2008 Verilog is now part of the same IEEE standard. It is commonly used in the semiconductor and electronic design industry as an evolution of Verilog.

SystemC is a set of C++ classes and macros which provide an event-driven simulation interface. These facilities enable a designer to simulate concurrent processes, each described using plain C++ syntax. SystemC processes can communicate in a simulated real-time environment, using signals of all the datatypes offered by C++, some additional ones offered by the SystemC library, as well as user defined. In certain respects, SystemC deliberately mimics the hardware description languages VHDL and Verilog, but is more aptly described as a system-level modeling language.

Institute of Electrical and Electronics Engineers scholarly society, publisher and standards organization, headquartered in US

The Institute of Electrical and Electronics Engineers (IEEE) is a professional association for electronic engineering and electrical engineering with its corporate office in New York City and its operations center in Piscataway, New Jersey. It was formed in 1963 from the amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers.

Rosetta resulted from the third approach with development beginning under the auspices of the Semiconductor Industry Council and the Air Force Research Laboratory. Originally developed by Perry Alexander and others at the University of Kansas, it was known simply as System-Level Design Language. [2] Standardization was transferred to VHDL International by 2000 and renamed Rosetta (after the Rosetta Stone) to reflect the heterogeneous nature of its specifications. Eventually, VHDL International and the Open Verilog Initiative merged to form Accellera, an industry sponsored consortium for electronic design automation (EDA) standards. A draft standard of Rosetta was published in November 2003 through Accellera. [3] Standardization was transferred to IEEE Design Automation Standards Committee (DASC) where it was developed by the Rosetta Working Group under IEEE project P1699 starting in March 2007. [4] [5] A draft of a language reference manual was published in April 2008, with editor Peter Ashenden of Australia. [6] The project was withdrawn in June 2013. [7]

Air Force Research Laboratory scientific research organization operated by the United States Air Force

The Air Force Research Laboratory (AFRL) is a scientific research organization operated by the United States Air Force Materiel Command dedicated to leading the discovery, development, and integration of affordable aerospace warfighting technologies, planning and executing the Air Force science and technology program, and providing warfighting capabilities to United States air, space, and cyberspace forces. It controls the entire Air Force science and technology research budget which was $2.4 billion in 2006.

University of Kansas Public university in Lawrence, Kansas, US

The University of Kansas, also referred to as KU, is a public research university with its main campus in Lawrence, Kansas, and several satellite campuses, research and educational centers, medical centers, and classes across the state of Kansas. Two branch campuses are in the Kansas City metropolitan area on the Kansas side: the university's medical school and hospital in Kansas City, the Edwards Campus in Overland Park, and a hospital and research center in the state's capital of Topeka. There are also educational and research sites in Garden City, Hays, Leavenworth, Parsons, and Topeka, and branches of the medical school in Salina and Wichita. The university is one of the 62 members of the Association of American Universities.

Rosetta Stone Ancient Egyptian stele with inscriptions in three languages

The Rosetta Stone is a granodiorite stele discovered in 1799 which is inscribed with three versions of a decree issued at Memphis, Egypt in 196 BC during the Ptolemaic dynasty on behalf of King Ptolemy V Epiphanes. The top and middle texts are in Ancient Egyptian using hieroglyphic and demotic scripts, while the bottom is in Ancient Greek. The decree has only minor differences among the three versions, so the Rosetta Stone became key to deciphering Egyptian hieroglyphs, thereby opening a window into ancient Egyptian history.


Rosetta is structured around three sub-languages that support defining various specification elements. The expression language defines basic functions and expressions used as terms and values in specifications. The expression language is a non-strict, purely functional, typed language in the spirit of Haskell. Functions are referentially transparent, encapsulated expressions and cannot have side effects. All Rosetta expressions have types that are determined statically. The type system is based on lifted sets where each type contains at least the bottom or undefined value. Any set can be used to define a type and any function that returns a set can be used to define a type former. Because type definitions can contain general Rosetta expressions, the type system is dependent.

The facet language defines individual specifications and specification composition to define systems. Facets and components define system models from one engineering perspective. Each facet is written by extending a domain that provides vocabulary and semantics for the model. Facets are defined by declaring items and defining properties for those items. As such, Rosetta is a declarative language and constructs cannot be guaranteed to evaluate to a value, although some facets can be evaluated. Using the design abstractions provided by its domain, a facet describes requirements, behavior, constraints, or function of a system. Facets are heterogeneous and may be defined using any of the predefined or user defined domains. The Rosetta semantics denotes each facet to a coalgebra that defines its model-of-computation. Because Rosetta is reflective, facets can be composed and transformed to define complex systems. A common specification technique is to write facets for different aspects of a system and then compose those aspects using product and sum operations to define the complete system.

The domain language defines specification domains otherwise known as specification types. The collection of domains forms a complete lattice ordered by homomorphism with the empty or null domain as its top element and the inconsistent or bottom domain as its bottom. There are three primary domain types. Units-of-semantics domains define basic units of specification. For example, the state_based domain defines the concept of state and next state without constraining the values or properties. Model-of-computation domains extend unit-of-semantics domains to define general computational models such as finite_state, continuous_time, discrete_time and frequency. Engineering domains extend model-of-computation domains to provide specification capabilities for specific engineering domains.

Since its early days, Rosetta expanded to include design domains such as hydraulic and mechanical systems, networking systems, security and trust, and software defined radios.

Further reading

Rosetta was influenced heavily by the non-strict, purely functional language Haskell, the Larch family of specification languages, and Prototype Verification System (PVS). A book devoted to the language was published in November 2006. [8]

Related Research Articles

Programming language Language designed to communicate instructions to a machine

A programming language is a formal language, which comprises a set of instructions that produce various kinds of output. Programming languages are used in computer programming to implement algorithms.

In computer engineering, a hardware description language (HDL) is a specialized computer language used to describe the structure and behavior of electronic circuits, and most commonly, digital logic circuits.

Electronic design automation (EDA), also referred to as electronic computer-aided design (ECAD), is a category of software tools for designing electronic systems such as integrated circuits and printed circuit boards. The tools work together in a design flow that chip designers use to design and analyze entire semiconductor chips. Since a modern semiconductor chip can have billions of components, EDA tools are essential for their design.

A modeling language is any artificial language that can be used to express information or knowledge or systems in a structure that is defined by a consistent set of rules. The rules are used for interpretation of the meaning of components in the structure.

The IEEE 1164 standard is a technical standard published by the IEEE in 1993. It describes the definitions of logic values to be used in electronic design automation, for the VHDL hardware description language. It was sponsored by the Design Automation Standards Committee of the Institute of Electrical and Electronics Engineers (IEEE). The standardization effort was based on the donation of the Synopsys MVL-9 type declaration.

Property Specification Language (PSL) is a temporal logic extending linear temporal logic with a range of operators for both ease of expression and enhancement of expressive power. PSL makes an extensive use of regular expressions and syntactic sugaring. It is widely used in the hardware design and verification industry, where formal verification tools and/or logic simulation tools are used to prove or refute that a given PSL formula holds on a given design.

Accellera organization

Accellera Systems Initiative is a standards organization that supports a mix of user and vendor standards and open interfaces development in the area of electronic design automation (EDA) and integrated circuit (IC) design and manufacturing. It is less constrained than the Institute of Electrical and Electronics Engineers (IEEE) and is therefore the starting place for many standards. Once mature and adopted by the broader community, the standards are usually transferred to the IEEE.

Verilog-AMS is a derivative of the Verilog hardware description language that includes analog and mixed-signal extensions (AMS) in order to define the behavior of analog and mixed-signal systems. It extends the event-based simulator loops of Verilog/SystemVerilog/VHDL, by a continuous-time simulator, which solves the differential equations in analog-domain. Both domains are coupled: analog events can trigger digital actions and vice versa.

Verilog-A is an industry standard modeling language for analog circuits. It is the continuous-time subset of Verilog-AMS.

Aldec, Inc. is a privately owned electronic design automation company based in Henderson, Nevada that provides software and hardware used in creation and verification of digital designs targeting FPGA and ASIC technologies.

Unified Power Format (UPF) is the popular name of the Institute of Electrical and Electronics Engineers (IEEE) standard for specifying power intent in power optimization of electronic design automation. The IEEE 1801-2009 release of the standard was based on a donation from the Accellera organization. The current release is IEEE 1801-2015.

The Design Automation Standards Committee (DASC) is a subgroup of interested individuals members of the Institute of Electrical and Electronics Engineers (IEEE) Computer Society and Standards Association. It oversees IEEE Standards that are related to computer-aided design. It is part of the IEEE Computer Society.

VHDL-AMS is a derivative of the hardware description language VHDL. It includes analog and mixed-signal extensions (AMS) in order to define the behavior of analog and mixed-signal systems.

SpecC is a System Description Language (SDL), or System-level Design Language (SLDL), and is an extension of the ANSI C programming language. It is used to aid the design and specification of digital embedded systems, providing improved productivity whilst retaining the ability to change a design at functional and specification level, unlike HDLs like Verilog and VHDL. An architectural model can be created which allows other tools to directly map the design onto silicon or FPGA. The main aim is for the reuse, exchange and integration of IP at various levels of abstraction.

High-level verification (HLV), or electronic system-level (ESL) verification, is the task to verify ESL designs at high abstraction level, i.e., it is the task to verify a model that represents hardware above register-transfer level (RTL) abstract level. For high-level synthesis, HLV is to HLS as functional verification is to logic synthesis.


  1. Perry Alexander and David Barton (June 2000). "Rosetta provides support for system-level design". EE Times. Archived from the original on August 16, 2000. Retrieved October 7, 2013.CS1 maint: uses authors parameter (link)
  2. "About SLDL and Rosetta". Original web site. University of Kansas. Archived from the original on March 18, 2004. Retrieved October 7, 2013.
  3. David Maliniak (November 10, 2003). "Rosetta Design Language On Road To Standardization". Electronic Design. Retrieved October 7, 2013.
  4. "Rosetta WG - Rosetta Systems Level Design Language Working Group". IEEE Standards Association. Retrieved October 7, 2013.
  5. Sherry Hampton (March 22, 2007). "P1699 - Standard for the Rosetta Systems Level Design Language Definition" (PDF). Project approval letter. IEEE Standards Association. Retrieved October 7, 2013.
  6. "P1699 Rosetta LRM subcommittee". April 22, 2008. Archived from the original on June 10, 2015. Retrieved October 7, 2013.
  7. "Standards Board New Standards Committee (NesCom) Recommendations" (PDF). IEEE Standards Association. June 14, 2013. Retrieved October 7, 2013.
  8. Perry Alexander (2006). System Level Design with Rosetta. Morgan Kaufmann. ISBN   978-1-55860-771-2.